Paper-cleaning apparatus



July 30, 1968 w. c. HERBERT, JR

PAPER-CLEANING APPARATUS Filed March 18, 1966 INVENTOR B WILLIAM C- HERBERIJR ATTORNEYS.

United States Patent 3,395,042 PAPER-CLEANING APPARATUS William C. Herbert, Jr., 79 Maryland Ave., Freeport, N.Y. 11520 Filed Mar. 18, 1966, Ser. No. 535,561 8 Claims. (Cl. 134-1) ABSTRACT OF THE DISCLOSURE A cleaning apparatus and method for removing foreign matter in which a vacuum cleaning area is defined by brushes through which a stream of air is caused to flow, and a means to neutralize electrostatic forces between the foreign matter and a surface to be cleaned.

This invention relates to an apparatus for cleaning sheets of paper, plastic, fabric and the like, and more particularly pertains to apparatus which includes means for electrostatically removing undesired dust particles and the like from such sheets or webs prior to printing, coating, calendering, etc. on such sheets or webs.

A major problem which plagues the printing industry in particular is that sheets of paper which are to be printed are often contaminated with dust and/or lint particles which are attracted to and maintained in engagement with the paper by forces of an electrostatic nature. Additionally, and to a lesser degree, other foreign particles are held on the sheet by gravitational forces and forces due to molecular attraction. When such contaminated sheets of paper are allowed to run through the printing press, the printing in'k adheres to the contaminating particles which, when they later fall off the paper, leave voids or specks in the printed surface, or the particles build up on cylinders, plates, etc. causing voids and specks.

While many solutions have been advanced in order to ameliorate the above-described problem, they usually have some drawbacks associated with their use. Thus, such solutions usually make extensive use of a rotating brush to clean the foreign matter from the sheets, such brush being positioned just prior to the printing station in the press, as in the United States patent to Walkup et al., Ser. No. 2,832,977. However, the rotating brush per se causes a static electrical charge to be built up in the sheet thereby causing the foreign particles again to adhere to the sheet. Additionally, and of greater importance, the par ticles per se build up on the brush and after an interval of time has elapsed the rotating brushes become ineffective to remove the particles. In some cases, the brushes actually begin to deposit foreign particles on the sheets of paper.

Accordingly, a desideratum of the present invention is to provide an apparatus for efficiently and effectively removing foreign particles from a sheet of any material, as paper, plastic, fabric and the like.

Another object of the present invention is to provide an apparatus for removing foreign particles from the surface of a sheet which includes means for neutralizing any electrostatic forces between the foreign particles and the sheet surface, and which further includes means for loosening the foreign particles and removing them from the surface of the sheet.

In furtherance of the above objects, the present invention includes means for subjecting the sheets surfaces to a stream of ions. A brush then loosens the particles and a vacuum head removes the particles from the sheet surfaces. The vacuum head is positioned to draw the ionic stream along the sheet and through the brush thereby subjecting the surfaces to the ionic stream for a sufficient interval of time to remove the electrostatic forces between Patented July 30, 1968 "ice the foreign particles and the sheet and simultaneously subjecting the brush to a continuous cleaning action.

A feature of the present invention resides in the novel details of construction which provides an apparatus of the type described wherein the bristles of the brushes form limited air barriers that define a cleaning area which is subjected to a continuous cleaning and electrically neutralizing ction.

Other and further objects of this invention reside in the structures and arrangements hereinafter more fully described with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of the surface cleaning apparatus constructed according to the present invention, illustrating its use in conjunction with the cleaning of a continuously moving web.

FIG. 2 is a sectional view of the mouth of the apparatus shown in FIG. 1, with parts broken away and to an enlarged scale, and

FIG. 3 is a side view of a modified embodiment of a cleaning apparatus constructed in accordance with the present invention, partially in section and with parts broken away, illustrating its use in conjunction with a sheet fed offset press.

While the term sheet of paper or sheet will be used throughout this specification, it is to be noted that this term is to be interpreted as applying to both a continuous web of material and to single sheets of material.

For convenience of description, the apparatus of the present invention is shown in FIGS. 1 and 2 for use in conjunction with the cleaning of a continuous web of paper 10 and is designated generally therein by the numeral 12. However, it is to be understood that references hereafter to printing processes and materials are not to be deemed a limitation on the scope of the invention. The principles and disclosure made hereafter is equally applicable to other materials and processes. The apparatus 12 includes a transversely extending vacuum head 14 which includes a front wall 16 (FIG. 2), a rear wall 18, and an intermediate or divider wall 20. The walls 16 and 20 define a passage 22 therebetween which communicates with a vacuum producing source 24 through a flexible coupling 26.

The vacuum source 24 includes an evacuator 28 which communicates with a collector bag 30 through a tube 32. A motor drives a fan (not shown) within the evacuator 28 to produce a vacuum in the passage 22 in the head 14. A movable damper 36 is interposed between the coupling 26 and the evacuator 28 to balance and control the amount of air flow through the vacuum head. Additionally the tube 32 may be alternatively connected to the outside air, a filter chamber, or a cyclone in accordance with the desires of the user.

The vacuum head 14- mounts a cover plate or current conducting housing 38 which extends rearwardly from the rear wall 18 and then downwardly to define an open ended transversely extending chamber 40 with respect to the wall 18. Received within the chamber 40 and connected to the rear Wall 18 of the head 14, by any conventional means, is an ionizing unit, designated generally by the numeral 42. The ionizing unit 42 includes a current conducting housing 38 having an open bottom and a central electrode 46 which is supported within the housing 38 and insulated therefrom by support blocks 44. The central electrode 46 includes a plurality of transversely spaced depending pointed members 48 which emit large quantities of high voltage charge at their extremities to ionize the air.

A source of potential 50 (FIG. 1) is connected to the ionizing unit 42 by a cable 52. One lead of the cable 52 is connected to the electrode 46 and the other lead is connected to the housing 38 thereby to establish a potential difference between the housing 38 and the electrode 46. The magnitude of the potential difference is suflicient to cause ionization of the air between the members 48 and the housing 38 thereby to produce a stream of ions.

Received within the head 14 in engagement with the walls and 18 is a brush support 54. The bottom of the brush support 54 is spaced from the wall 18 to define a slot 56 therebetween which communicates with a recess 58 in the support. Removably received within the recess 58 is a transversely extending rod 60 having a plurality of transversely spaced depending bristles or tufts 62 which define a transversely extending brush 64. Similarly, another transversely extending brush support 66 is connected to the inner surface of the front wall 16 of the vacuum head 14 and it is in spaced relation to the wall 20.

The brush support 66 includes a lower portion that is spaced from the Wall 16 to define a slot 68 therebetween which communicates with a recess 70 in the brush support. A brush 72 is received Within the brush support 66 and comprises a transversely extending rod 74 having transversely spaced depending bristles or tufts 76. The brushes 64 and 72 extending for the length of the head 14, are slidably received in the respective brush supports 54 and 66 and may therefore be easily removed and replaced when their bristles have been worn. The spacing of the tufts of the brushes 64 and 72 form limited air barriers that define the sides of the cleaning area therebetween.

In operation, the apparatus 12 is normally positioned in front of the first printing station of the printing press or where cleaning is otherwise required. Additionally, the head 14 is spaced above the Web 10 by a distance not exceeding the height of the brushes 64 and 72 so that the bottom of the brushes contact the upper surface of the web 10. It is assumed that the continuous Web of paper 10 moves in the direction indicated by the arrowheads 78. Accordingly, every portion of the web 10 Will first pass below the members 48 and thereby be subjected to a stream of ions which are produced in the manner noted above.

The charged particles 80 will neutralize the electrostatic forces between the dust, lint or other contaminating foreign particles and the sheet of paper 10. As the web 10 continues to move in the direction 78, the neutralized foreign particles will be brushed by the brush 64 thereby loosening the particles from the surface of the paper. Additionally, the brush 64 loosens any foreign particles which may adhere to the web 10 due to gravitational forces and forces due to molecular attraction between the foreign particles and the sheet 10. The vacuum produced in the passage 22 due to the vacuum producing apparatus 24 causes the ionic stream to move in the direction indicated by the arrowheads 82 toward, through and between the limited space barrier afforded by the bristles 62 of the brush 64.

Accordingly, it is to be noted that the stream of ions is therefore carried along with the surface of the web 10 thereby continuously subjecting an area of the surface of the web 10 to the stream of ions 80, albeit the area has moved from below the member 48. Additionally, the vacuum action of the head 14 causes the stream of ions 80 to fiow through the tufts 62 and up into the passage 22 thereby subjecting the brush 64 to a continuous cleaning and neutralizing action. Accordingly, the build-up of static charge on the brush 64 thereby is prevented even though there is a continuous rubbing action between the brush 62 and the web 10. Thus, the brush 64 is maintained free from the accumulation of foreign particles thereon. After the portion of the web 10 under consideration passes below the brush 64, the loosened foreign matter will essentially be trapped within the cleaning area defined by the two brushes 64 and 72.

It is to be noted that the vacuum in the passage 22 will also cause air to flow in a direction opposite to the direction of movement of the web 10, as indicated by the arrowheads 84, through limited space or barrier afforded by the bristles 76 of brush 72 and into the passage. Ac-

cordingly, the loose foreign particles entrapped between the brushes 72 and 64 will be sucked into the passage 22 and, hence, through the coupling 26 and the evacuator 28 into the collector bag 30. Similarly to the brush 64, the air flow in the direction of the arrows 84 passes through the brush 72 thereby to continuously clean the brush 72 and maintain the brush free from foreign or undesired particles such as dirt and/or lint.

Accordingly, a cleaning apparatus has been provided for removing foreign particles from a continuously moving web of any kind of material in a highly efficient and effective manner.

Those skilled in the art will recognize that the transverse space between the brushes 64 and 74 forms an area that is still subject to the flow of ions from the ionizing unit 46 even after the subjected portion of the web 10 moves from directly below the unit 46. In this area all static electrical forces are neutralized to enable the quick and simple removal of contaminating foreign particles from the moving web.

Although the apparatus 12 above disclosed was described in conjunction with a printing press utilizing a continuously moving web of paper which receives the printing matter thereon, the present invention is equally applicable to printing presses of the offset type which utilize individual cut sheets of paper or other machines which utilize other materials. Thus, FIG. 3 illustrates a modified embodiment of the present invention adapted to be used in conjunction with a sheet fed offset press.

The cleaning apparatus is designated generally by the number 112 in FIG. 3 and includes a stationary vacuum head section 114 and an adjustable vacuum head section 115. Provided in the vacuum head 114 is a passage 122 which communicates with a passage (not shown) in the head 115. The head mounts a pair of opposed depending removable brushes 164 and 172 which are positioned on each side of the passage in the head 115 to form limited air barriers that define the sides of a cleaning area therebetween. Provided on the rear of the head 115 is an ionizing unit 142 whichv operates in a manner similar to the ionizing unit 42.

The head 115 is adjusted relative to an impression cylinder 186 so that the mouth of the passage in the head 115 is spaced above the cylinder 196 and the brushes 172 and 164 contact the cylinder. As is conventional in an offset type of printing operation, the impression cylinder 186 carries sheets of paper thereon. Additionally, a brush pressure adjusting rod and bracket assembly 188 of conventional design is provided to adjust the pressure with which the removable brushes 164 and 172 bear upon the cylinder 186.

The operation of the apparatus 112 is identical to the operation of the apparatus 12 in that the ionizing unit 142 produces a stream of ions which are directed toward and carried along with the sheets of paper moved by the impression cylinder 186 due to the vacuum applied to the passage 122 and the passage in the head 115. The bristles of the brush 164 loosen the foreign particles on the sheets of paper which are then entrapped between the brushes 164 and 172. Additionally, the stream of ions and the air are drawn through the limited air barrier or space afforded between the bristles of brushes 164 and 172 in a manner similar to the flow of static eliminating ions through the respective brushes 64 and 72, thereby to continuously clean the brushes and maintain the brushes free from the build-up of foreign particles thereon.

When utilizing the present invention in connection with printing presses as described and with other machines, it is sometimes necessary that both sides of the web or sheet of moving material be efficiently cleaned. To this end it will be apparent to those who are skilled in the art that the embodiments of the present invention may be positioned on opposite sides of the sheet when the same must be cleaned.

While there have been shown and described and 3 pointed out the fundamental novel features of the invention as applied to several preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated and in their operations may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to be limited on y as indictaed by the scope of the claims appended hereto.

I claim: 1. Cleaning apparatus for removing foreign matter from a moving sheet comprising ionizing means in spaced relation to the sheet for subjecting the sheet and matter thereon to a stream of ions to neutralize electrostatic forces between the sheet and the matter, first brush means located beyond said ionizing means in the direction of the movement of the sheet and adapted to engage the sheet for loosening the foreign matter from the sheet, vacuum means positioned beyond said first brush means in the direction of movement of the sheet for drawing said stream of ions along the sheet and through said first brush means to continuously remove the foreign matter from the sheet, and second brush means positioned beyond said vacuum means in the direction of movement of the sheet for entrapping the foreign matter between said first and second brush means. said vacuum means includes a head extending transversely across the sheet, and means for connecting said head to a source of vacuum, the spacing of the tufts of said first and second brush means forming limited air barriers that define the sides of a cleaning area therebetween. 2. A cleaning apparatus according to claim 1, said vacuum means being positioned such that the same causes a stream of ions to flow from said ionizer means through the tufts of said first brush means to clean and maintain the tufts clean of foreign particles while causing air to flow between the tufts of the second brush means into the cleaning area to trap the foreign particles in the cleaning area for evacuation therefrom by said vacuum means. 3. Cleaning apparatus according to claim 2, and means for removably connecting said first brush means and said second brush means to said head. 4. Cleaning apparatus for removing foreign matter from a moving sheet according to claim 1,

and pressure adjusting means connected to said head for adjusting the pressure applied to said first brush means. 5. Cleaning apparatus as in claim 2, in which said ionizing means comprises a first electrode extending transversely across said sheet and a second electrode in spaced relation to said first electrode,

and means for connecting said first and second electrodes with a source of potential. 6. Cleaning apparatus according to claim 5, wherein said first electrode is provided with a plurality of spaced depending pointed members,

said members being directed at the sheet for directing an ion stream toward the sheet. 7. A method for removing foreign particles from a moving sheet comprising 10 directing an ionic stream of particles at the sheet, brushing the sheet with a first brush to loosen the foreign particles thereon, and simultaneously drawing the ionic stream along the sheet, through the bristles of the brush and away from the sheet to neutralize electrostatic forces at the first brush to remove the loosened foreign particles from the sheet, entrapping the loosened particles between the first brush and a second brush simultaneously with the removal of the loosened particles from the sheet,

and drawing air through the second brush in a direction opposite to the direction of movement of the sheet to continuously clean the second brush.

8. Cleaning apparatus for removing foreign particles from a moving sheet prior to printing material on the sheet comprising a first and second brush spaced from each other to define a cleaning area therebetween,

ionizing means positioned adjacent said first brush and remote from said cleaning area for subjecting the sheet and particles thereon to a stream of ions to neutralize electrostatic forces between the sheet and the particles,

the bristles of said first and second brushes forming limited air barriers along the cleaning area which they define to permit the passage of air between the bristles from outside the cleaning area into the cleaning area in response to vacuum means,

and vacuum means overlying said cleaning area for drawing said ion stream through said first brush and air through said second brush and for removing the particles within said cleaning area.

FOREIGN PATENTS 629,418 4/1936 Germany.

ROBERT W. MICHELL, Primary Examiner. 

